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Commit a44b56d3 authored by Kevin Hilman's avatar Kevin Hilman Committed by Linus Torvalds
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[PATCH] slab debug and ARCH_SLAB_MINALIGN don't get along 



When CONFIG_SLAB_DEBUG is used in combination with ARCH_SLAB_MINALIGN, some
debug flags should be disabled which depend on BYTES_PER_WORD alignment.

The disabling of these debug flags is not properly handled when
BYTES_PER_WORD < ARCH_SLAB_MEMALIGN < cache_line_size()

This patch fixes that and also adds an alignment check to
cache_alloc_debugcheck_after() when ARCH_SLAB_MINALIGN is used.

Signed-off-by: default avatarKevin Hilman <khilman@mvista.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent cace673d

mm/slab.c

+11 −6
Original line number Diff line number Diff line
@@ -2197,18 +2197,17 @@ kmem_cache_create (const char *name, size_t size, size_t align, 
	if (flags & SLAB_RED_ZONE || flags & SLAB_STORE_USER)

		ralign = BYTES_PER_WORD;



	/* 2) arch mandated alignment: disables debug if necessary */

	/* 2) arch mandated alignment */

	if (ralign < ARCH_SLAB_MINALIGN) {

		ralign = ARCH_SLAB_MINALIGN;

		if (ralign > BYTES_PER_WORD)

			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);

	}

	/* 3) caller mandated alignment: disables debug if necessary */

	/* 3) caller mandated alignment */

	if (ralign < align) {

		ralign = align;

	}

	/* disable debug if necessary */

	if (ralign > BYTES_PER_WORD)

		flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);

	}

	/*

	 * 4) Store it.

	 */
@@ -3063,6 +3062,12 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, 


		cachep->ctor(objp, cachep, ctor_flags);

	}

#if ARCH_SLAB_MINALIGN

	if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {

		printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",

		       objp, ARCH_SLAB_MINALIGN);

	}

#endif

	return objp;

}

#else